Core for motion picture films



Oct. 4, 1932 K. c. D. HICKMAN CORE FOR MOTION PICTURE FILMS Filed Feb. 8, 1929 Patented Oct. 4, 1932 warren srrns OFFICE KENNETH C. D. HICKMAN, OF ROCHESTER, NEW YORK, ASSIGNOR TO EASTMAN KODAK COMPANY, OF ROCHESTER, NEW YORK, A CORPORATION OF NEW YORK CORE FOR MOTION PICTURE FILMS Application filed February 8, 1929, Serial No. 338,580, and in Great Britain October 9, 1928.

lo customary to wind the film upon a central core of wood, but these cores have been found to emit vapours which damaged the film. Further, experience shows that quite small deformatory forces at the circumference of 15 the roll produce such powerful forces at the centre that extremely strong cores must be employed, and that metal cores, unless of prohibitive weight and consequent expense, readily tend to bend.

According to this invention a core is made from cellulosic material of the same or of substantially similar composition as that of the base of the motion picture film wound upon it. Such a core possesses the necessary strength and can be moulded or otherwise formed so as to possess the necessary mechanical strength coupled with the required resiliency.

Preferably the core is formed by winding upon a mandrel a strip of cellulosic material with a layer of film cement or solvent between each convolution, the annular core thus formed being removed from its mandrel and subjected to heat until it is free from solvent.

If \vaste film from which the photographic emulsion and all dirt has been removed is used as the strip of cellulosic material from which the core is wound, the article can be cheaply produced and being of similar composition to the base of the motion picture film there can be no injurious interaction between the film and the core.

Further it has been found that a core so formed possesses extreme resiliency and mechanical strength and constitutes an ideal matrix on which to wind motion picture film for storage and for distribution from the factory.

Reference will be made to the accompanying drawing in the several figures of which the same reference characters denote the same parts and in which:

Figure 1 is a perspective View of a completed film core, and

Fig. 2 is a diagrammatic side elevation of a device for making the hubs.

I prefer to make my hub in the following manner: The hub designated broadly as 1 is composed of a suitable number of convolutions 2 of a plastic composition including a cellulosic derivative in strip form 3.

The material can be conveniently drawn from a roll 4 of suitable width past a nozzle 5 which supplies solvent 6 to the'strip in advance of the coiling operation. The flow of solvent from a supply tank 7 may be controlled by a valve 8.

I wind the strip material upon a hub pref erably made up of a plurality of collapsible sections 9 and these may be supported by a guide plate 10 against which one edge of the strip material is coiled. When the core has reached the desired size the solvent flow is stopped and the strip out.

Any of the known volatile solvents or cements containing a volatile solvent may be used. Instances are found in the patents: Cook, 1,690,622, Nov. 6, 1928; Tessler, 1,122,554, Dec. 29, 1914; Thornton, 1,649,756, Nov. 12, 1927; Griffin, 1,596,965, Aug. 24, 1926, and elsewhere.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is As an article of manufacture and sale, a roll film package including in combination a core comprising an uncoated strip of a composition including a cellulose derivative wound upon itself and the successive convolutions thereof integrally united together and a strip of motion picture film wound thereon in convolutions, the motion picture film comprising a support of the same cellulose derivative as the core and carrying a photographic emulsion layer.

Signed at Rochester, New York, this 1st day of February 1929.

KENNETH G. D. HICKMAN. 

